There are many and varied types of product cartons in the prior art. Some of them can be folded into a flat state and erected to form a tray for receiving a product such as food products. Others can be folded in a flat state for storage and then erected to form a closed container for holding a product.
In the fast food industry especially, a package is required which can be easily opened, filled with the product, closed and then reopened to gain access to the product and to reclose it if desired. Such prior art packages for the fast food industry are generally of styrofoam or similar material which can be stacked one within the other for storage purposes. When used, the food products are placed in a bowl-shaped depression on one side of the package and the other side is folded about a hinge and locked to the bottom portion with a tab in a slot. This container can of course be opened and closed repeatedly. However, if the containers are to be used in a location with restricted space, such as on an airplane, the bowl-shaped containers, even though they stack within each other, require a significant amount of space. Further, the prior art containers require a closure of some type, generally a slot with a projection that is inserted in the slot to lock the two halves together.
The present invention provides a carton that is formed from a paperboard blank and which can be first folded in a substantially flat state for storage, unfolded, second, to form a tray with a bottom wall and vertical side walls and end walls for receiving the product and can be further folded, third, to form a box-like structure that encloses the product totally. The scoring of the carton allows it to fold and close easily. Further, unique diagonal score lines on the side walls allow the carton, when folded to the box-like structure, to fold its side walls around and over the product, thus holding the product securely in the container. In addition, this unique diagonal scoring on the side walls interacts against and with the product to result in a resilient, self-locking closure that does not require special locks or locking devices. Further, when opened from the box-like structure to the tray, space is provided on each side of the center portion of the tray where the product is located to allow additional product such as french fries to be placed therein. The blank can also be formed such that it can be pre-setup by machine although in such case, the tray cannot be folded to a flat state from its erected state. Also, the blank can be formed such that, when erected into a rectangular tray, a plurality of the rectangular trays can be nested within each other to conserve space.
Thus the present invention relates to a product carton that can be folded to a substantially flat state for storage, erected as a tray having a bottom wall, vertical side walls and end walls for receiving a product, and further folded to form a box-like structure that totally encloses the product.
It is an important object of the present invention to provide a carton that utilizes score lines on the side wall panels to cause an interaction between the side wall panels and the product which results in a self-locking box-like structure.
It is another important object of the present invention to provide a product carton which has a plurality of spaced inverted V-shaped score lines on each side wall panel to cause the side wall panels to fold around and over the product, thus holding it securely in place in the container.
It is yet another object of the present invention to provide a product carton that can be pre-setup by machine but cannot be folded to a flat state.
It is also another object of the present invention to provide a product carton that, when erected to form a substantially rectangular tray, can be nested one within the other for purposes of conserving space.